The late-spring sun is cranking up the heat. It’s hard to
believe the long, cold winter
is still causing problems in Georgia landscapes.

"We’ve had a lot of Botrytis blight in landscape plants
this spring," said
Jean Williams-Woodward, a plant pathologist with the University
of Georgia Extension
Service.

Botrytis blight is caused by a fungus, Botrytis
cinerea, she said. Commonly
known as "gray mold," it’s the most common pathogen in
any greenhouse, nursery
or landscape. It attacks any aboveground part of many vegetable
and landscape plants.

"Botrytis is always a problem for any flowering
plant," Williams-Woodward
said. "The problem this spring has been mostly in bedding
plants. It hasn’t been too
bad in woody ornamentals."

The problem started, she said, in the state’s greenhouses,
mostly because of the winter
that didn’t want to end.

"Greenhouse growers had all these bedding plants ready
to go, but it was still too
cold," Williams-Woodward said. "They couldn’t sell
them."

Waiting for spring sales to rev up, growers wound up having
to hold the plants a month
longer than they normally would have. And the plants suffered
from having to be held so
long. Some flowers dropped off, and leaves yellowed.

Now the plants are in the landscape, where Botrytis is easier
to control because the
plants are more spread out. But it’s still something to contend
with.

Because the injured and yellowing tissues are more
vulnerable, Williams-Woodward said
Botrytis blight could be more of a problem in landscapes this
year.

Botrytis attacks these old flowers and leaves and other weak
tissues first, she said.
Then it spreads into healthy tissue. On bedding plants, Botrytis
often causes leaf spots
when infected flowers drop onto leaves. It’s most active under
wet conditions and when the
humidity is high and the air is stagnant.

Williams-Woodward said the fungus is easy to identify. With a
magnifying glass, and
often without it, she said, you can see a gray-brown web and
grape-like clusters of spores
on infected tissues.

"The spores are dry and are easily dispersed by air
movement," she said.
"Overhead watering and rain disperse the spores, too. The
force of the water droplet
landing on a leaf creates a shock wave that dislodges the spores
into the air."

Splashing water droplets can carry the spores to nearby
plants, too.

"Pick up a plant with Botrytis sometime and gently flick
the infected plant
part," she said. "A cloud of spores can usually be
seen floating in the air
above the plant."

Controlling Botrytis in the landscape takes a little cleaning
up, using a fungicide and
maybe changing a few things around your plants.

"Prune dead and injured stems from cold-damaged
plants," Williams-Woodward
said. "Clean the ground (and the inside of pots) of dead,
fallen leaf litter. And
remove yellowing leaves from the base of plants."

People who pay regular attention to their plants can prevent
the spread of the fungus.
Picking off and discarding spent flowers and yellowing leaves as
they show up will often
keep plants healthy.

You may need to space your plants farther apart, too, to
allow for better air
circulation. If Botrytis is a problem, don’t use overhead
irrigation, she said.

Because the fungal spores spread around so easily, fungicides
can be important in
controlling Botrytis.

"Spray a protective fungicide after the plants are free
of blighted tissue,"
Williams-Woodward said. "Consult your county agent to find
out which fungicide to use
for a particular plant."